The human rotavirus strain PA169 (VP7 serotype 6) which was originally isolated from a child with diarrhea was found to possess a new VP4 neutralization specificity distinct from ten known VP4 serotypes. This is the sixth human rotavirus VP4 serotype. The bovine rotavirus strain NCDV-Cody which was originally isolated from a diarrheic calf and traditionally considered as the virulent counterpart for the attenuated NCDV-Lincoln (VP7 serotype 6) was shown to belong to VP7 serotype 8.